1 The flux is very effective. 2 Is not corrosive to the IC and PCB. 3 Having a boiling point only slightly higher than the melting point of the solder. Welding solder melts soon begins to boil the endothermic vaporization IC and PCB temperature can be maintained at this temperature the truth and we boil water truth is as long as the water pot warming will not burn out. Please note that the photo will occur some aberration Goods in kind prevail.